Distribution and habitat of the critically endangered Capricorn Yellow Chat Epthianura crocea macgregori.

Abstract

The Capricorn Yellow Chat (Meliphagidae: Epthianura crocea macgregori) is a poorly known, endangered passerine of coastal north-eastern Australian wetlands. Recent research has highlighted the need for evidence based management and that recovery programmes may be hampered by a lack of sound ecological knowledge. Capricorn Yellow Chats were found at 15 sites near Rockhampton between Broad Sound and the Fitzroy River delta in the south. Overall, suitable habitat was limited with an area occupied of about 6 000 ha, confirming the need for careful management. Habitat may be typified as grass-sedge wetlands or tall supratidal saltmarshes that are temporarily flooded, with pools becoming brackish to hypersaline as they dry. Over 96% of sightings were on coastal plains formed by marine sedimentation processes, most without current tidal influence, and many less than 5 m above sea level. The remaining 4% were associated with alluvial-formed plains, but only where these bordered existing marine plain sites; suggesting a preference for marine plain habitats, possibly reflecting structural differences and foraging preferences (marine plains tend to be more open due to the presence of salt-tolerant samphire vegetation). Sea level rise was identified as a major threat to the subspecies with chat sightings at most sites averaging less than 2 m above current highest astronomical tidal influence, and sites becoming tidal or with regular storm surge influence under future modest predicted sea level rise scenarios of 0.5 m by 2100. Most sites had some form of banking to reduce tidal influence and promote freshwater pasture grasses for cattle production. The site supporting most chats had small banks that allowed floods to flow around them, maintaining connectivity with the downstream marine systems. This study contributes to baseline information essential to the evaluation of any future management interventions; thus avoiding the pitfalls hampering much of the global conservation efforts directed at threatened species.

Breeding cues in a wetland-dependent Australian passerine of the seasonally wet-dry tropics

“…Like all chats, it is adapted for foraging on the ground and over low vegetation (Schodde ) and has relatively long legs and toes (Keast ; Matthew ). Capricorn yellow chats are sexually dimorphic and undertake local movements between discrete patches of habitat (Houston ). Pairs build concealed nests in low vegetation close to the ground with both involved in parental care (Houston et al .…”

“…Capricorn yellow chats have been observed feeding on caterpillars, spiders, damsel flies (Odonata), moths and winged ants (Houston et al . ,b; Houston ).…”

“…One subspecies, the Capricorn yellow chat, E. crocea macgregori , has a very restricted distribution centred on the marine plains of coastal central Queensland, where it breeds in ephemeral and seasonally flooded wetlands and is typified by a labile breeding season (Houston et al . ; Houston ). Most areas where the species occurs, including the Capricorn subspecies, are characterized by highly variable rainfall regimes.…”

Biocontrol of Harrisia cactus Harrisia martinii by the mealybug Hypogeococcus festerianus (Hemiptera: Pseudococcidae) in salt‐influenced habitats in Australia

“…Vegetation here is influenced by wet season rainfall causing inundation of pools followed by rapid drying, leading to elevated salinities several times greater than that of sea water and extremes of water stress (Houston et al 2013). Harrisia cactus occurred on the edges of higher ground with salt-tolerant vegetation such as marine couch (Sporobolus virginicus (L.) Kunth) and samphire (Tecticornia spp.).…”

“…Harrisia cactus also occurred in grassland at slightly higher elevations on bordering alluvial plains. Vegetation here is influenced by wet season rainfall causing inundation of pools followed by rapid drying, leading to elevated salinities several times greater than that of sea water and extremes of water stress (Houston et al 2013). Some habitats receive occasional tidal inundation, although not the bordering edges where Harrisia cactus occurs.…”